Solid-state imaging device and driving method thereof, and electronic apparatus

ABSTRACT

The present technology relates to a solid-state imaging device and a driving method thereof, and an electronic apparatus that make it possible to improve the precision of phase difference detection while suppressing deterioration of resolution in a solid-state imaging device having a global shutter function and a phase difference AF function. Provided is a solid-state imaging device including: a pixel array unit including, as pixels including an on-chip lens, a photoelectric conversion unit, and a charge accumulation unit, imaging pixels for generating a captured image and phase difference detection pixels for performing phase difference detection arrayed therein; and a driving control unit configured to control driving of the pixels. The imaging pixel is formed with the charge accumulation unit shielded from light. The phase difference detection pixel is formed in a manner that at least part of at least one of the photoelectric conversion unit and the charge accumulation unit refrains from being shielded from light. The present technology can be applied to, for example, a CMOS image sensor.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/244,385, filed Jan. 10, 2019, which is a continuation ofU.S. patent application Ser. No. 16/243,915, filed Jan. 9, 2019, whichis a continuation of U.S. patent application Ser. No. 15/926,528, filedMar. 20, 2018, now U.S. Pat. No. 10,510,786, which is a continuation ofU.S. patent application Ser. No. 14/898,942, filed Dec. 16, 2015, nowU.S. Pat. No. 9,941,314, which is a National Stage Entry ofPCT/JP2014/066566, filed Jun. 23, 2014, which claims the benefit ofpriority from prior Japanese Patent Application Nos. JP 2013-141761,filed Jul. 5, 2013, and JP 2014-093510, filed Apr. 30, 2014, the entirecontents of which are hereby incorporated by reference.

TECHNICAL FIELD

The present technology relates to solid-state imaging devices anddriving methods thereof, and electronic apparatuses. The presenttechnology particularly relates to a solid-state imaging device and adriving method thereof, and an electronic apparatus that make itpossible to improve the precision of phase difference detection whilesuppressing deterioration of resolution in a solid-state imaging devicehaving a global shutter function and a phase difference AF function.

BACKGROUND ART

There conventionally have been solid-state imaging devices thatimplement an auto focus (AF) function by mixing phase differencedetection pixels among imaging pixels. Such a solid-state imaging deviceimplements an AF function (hereinafter called phase difference AFfunction) of a phase difference detection method by shielding differenthalves of the respective photoelectric conversion units of a pair ofphase difference detection pixels from light and using a differencebetween the respective outputs of the pair of phase difference detectionpixels.

There also have been solid-state imaging devices that implement a globalshutter function by including, in each pixel, a charge retention unitthat retains charge transferred from a photoelectric conversion unit.Such a solid-state imaging device implements the global shutter functionby performing transfer and retention of charge in all the pixelssimultaneously so that exposure periods coincide among all the pixels.

Furthermore, solid-state imaging devices having both the global shutterfunction and the phase difference AF function have been proposed inrecent years (e.g., see Patent Literatures 1 and 2).

CITATION LIST Patent Literature

Patent Literature 1: JP 2007-243744A

Patent Literature 2: JP 2012-151774A

SUMMARY OF INVENTION Technical Problem

In the technology of Patent Literature 1, one phase difference detectionpixel includes two sets of a photoelectric conversion unit and a chargeretention unit. Therefore, the light-receiving area of the photoelectricconversion unit is reduced and the sensitivity of the phase differencedetection pixel is lowered, resulting in lowered precision of phasedifference detection.

In the technology of Patent Literature 2, a set of two pixels of animaging pixel and a phase difference detection pixel is formed.Therefore, the number of effective pixels of the whole solid-stateimaging device is reduced by half and the resolution of the output imageis lowered.

The present technology, which has been made in view of suchcircumstances, makes it possible to improve the precision of phasedifference detection while suppressing deterioration of resolution in asolid-state imaging device having a global shutter function and a phasedifference AF function.

Solution To Problem

According to an aspect of the present technology, there is provided asolid-state imaging device including: a pixel array unit including, aspixels including an on-chip lens, a photoelectric conversion unit, and acharge accumulation unit, imaging pixels for generating a captured imageand phase difference detection pixels for performing phase differencedetection arrayed therein; and a driving control unit configured tocontrol driving of the pixels. The imaging pixel is formed with thecharge accumulation unit shielded from light. The phase differencedetection pixel is formed in a manner that at least part of at least oneof the photoelectric conversion unit and the charge accumulation unitrefrains from being shielded from light.

The driving control unit can read, in performing the phase differencedetection, charge accumulated in at least part of at least one of thephotoelectric conversion unit and the charge accumulation unit in thephase difference detection pixels, and perform, in generating thecaptured image, accumulation of charge in at least the imaging pixelssimultaneously.

The phase difference detection pixel can include a light-shielding filmthat is provided with an opening in at least part of at least one of thephotoelectric conversion unit and the charge accumulation unit. In apair of the phase difference detection pixels, the openings can beprovided in positions symmetrical to each other in a first direction inwhich the pair of phase difference detection pixels are arrayed, withrespect to optical axes of the on-chip lenses.

The charge accumulation unit can be formed as a charge retention unitconfigured to retain charge from the photoelectric conversion unit.

The photoelectric conversion unit and the charge retention unit can beformed side by side in the first direction. The photoelectric conversionunit can be provided with the opening in one of the pair of phasedifference detection pixels, and the charge retention unit can beprovided with the opening in the other of the pair of phase differencedetection pixels.

In performing the phase difference detection, the driving control unitcan read charge accumulated in the photoelectric conversion unit in theone phase difference detection pixel, and read charge accumulated in thecharge retention unit in the other phase difference detection pixel.

The driving control unit can control driving of the one phase differencedetection pixel and the other phase difference detection pixel in amanner that a product of sensitivity of the photoelectric conversionunit and accumulation time in the one phase difference detection pixelbecomes equal to a product of sensitivity of the charge retention unitand accumulation time in the other phase difference detection pixel.

The photoelectric conversion unit and the charge retention unit can beformed side by side in the first direction. Approximately half of thephotoelectric conversion unit in the first direction can be providedwith the opening in one of the pair of phase difference detectionpixels, and the other approximately half of the photoelectric conversionunit in the first direction can be provided with the opening in theother of the pair of phase difference detection pixels.

In the pair of phase difference detection pixels, the photoelectricconversion units and the charge retention units can be formed inpositions with mirror symmetry with respect to a boundary between thepair of phase difference detection pixels. In each of the pair of phasedifference detection pixels, the photoelectric conversion unit can beprovided with the opening.

The photoelectric conversion unit and the charge retention unit can beformed side by side in a second direction perpendicular to the firstdirection. Approximately half of the photoelectric conversion unit andthe charge retention unit in the first direction can be provided withthe opening in one of the pair of phase difference detection pixels, andthe other approximately half of the photoelectric conversion unit andthe charge retention unit in the first direction can be provided withthe opening in the other of the pair of phase difference detectionpixels.

In performing the phase difference detection, the driving control unitcan read charge accumulated in the photoelectric conversion unit and thecharge retention unit in the one phase difference detection pixeltogether, and read charge accumulated in the photoelectric conversionunit and the charge retention unit in the other phase differencedetection pixel together.

In the phase difference detection pixel, the charge accumulation unitcan be formed as another photoelectric conversion unit side by side withthe photoelectric conversion unit in the first direction. Thephotoelectric conversion unit can be provided with the opening in one ofthe pair of phase difference detection pixels, and the otherphotoelectric conversion unit can be provided with the opening in theother of the pair of phase difference detection pixels.

In the phase difference detection pixel, the photoelectric conversionunit and the charge accumulation unit can be formed in positionssymmetrical to each other in a predetermined direction, with respect toan optical axis of the on-chip lens. In performing the phase differencedetection, the driving control unit can read charge accumulated in thephotoelectric conversion unit in the phase difference detection pixeland charge accumulated in the charge retention unit in the phasedifference detection pixel separately.

The charge accumulation unit can be formed as a charge retention unitconfigured to retain charge from the photoelectric conversion unit.

The phase difference detection pixel can include a light-shielding filmthat is provided with openings in part of the photoelectric conversionunit and the charge accumulation unit. The openings can be provided inpositions symmetrical to each other in the predetermined direction, withrespect to an optical axis of the on-chip lens.

The charge accumulation unit can be formed as a charge retention unitconfigured to retain charge from the photoelectric conversion unit. Thephase difference detection pixel can include a transfer electrodeconfigured to transfer charge from the photoelectric conversion unit tothe charge retention unit above the charge retention unit. The transferelectrode can be formed using a transparent conductive film.

At least one of the imaging pixel and the phase difference detectionpixel can share constituent elements among a plurality of pixels.

The constituent elements shared by the plurality of pixels can includeat least one of a floating diffusion region, a reset transistor, anamplifier transistor, and a selection transistor.

According to an aspect of the present technology, there is provided adriving method of a solid-state imaging device, the solid-state imagingdevice including a pixel array unit including, as pixels including anon-chip lens, a photoelectric conversion unit, and a charge accumulationunit, imaging pixels for generating a captured image and phasedifference detection pixels for performing phase difference detectionarrayed therein, and a driving control unit configured to controldriving of the pixels. The imaging pixel is formed with the chargeaccumulation unit shielded from light. The phase difference detectionpixel is formed in a manner that at least part of at least one of thephotoelectric conversion unit and the charge accumulation unit refrainsfrom being shielded from light. The driving method includes the stepsof: reading, in the phase difference detection performed by thesolid-state imaging device, charge accumulated in at least part of atleast one of the photoelectric conversion unit and the chargeaccumulation unit in the phase difference detection pixels; andperforming, in generation of the captured image by the solid-stateimaging device, accumulation of charge in at least the imaging pixelssimultaneously.

According to an aspect of the present technology, there is provided anelectronic apparatus including a solid-state imaging device including apixel array unit including, as pixels including an on-chip lens, aphotoelectric conversion unit, and a charge accumulation unit, imagingpixels for generating a captured image and phase difference detectionpixels for performing phase difference detection arrayed therein, and adriving control unit configured to control driving of the pixels. Theimaging pixel is formed with the charge accumulation unit shielded fromlight. The phase difference detection pixel is formed in a manner thatat least part of at least one of the photoelectric conversion unit andthe charge accumulation unit refrains from being shielded from light.

In an aspect of the present technology, as pixels including an on-chiplens, a photoelectric conversion unit, and a charge accumulation unit,imaging pixels for generating a captured image and phase differencedetection pixels for performing phase difference detection are arrayed.The imaging pixel is formed with the charge accumulation unit shieldedfrom light. The phase difference detection pixel is formed in a mannerthat at least part of at least one of the photoelectric conversion unitand the charge accumulation unit refrains from being shielded fromlight.

Advantageous Effects of Invention

According to an aspect of the present technology, it is possible toimprove the precision of phase difference detection while suppressingdeterioration of resolution in a solid-state imaging device having aglobal shutter function and a phase difference AF function.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating an embodiment of an electronicapparatus including an image sensor to which the present technology isapplied.

FIG. 2 is a block diagram illustrating an example configuration of animage sensor.

FIG. 3 illustrates an example of the pixel arrangement of an imagesensor.

FIG. 4 is a flowchart illustrating imaging processing by an electronicapparatus.

FIG. 5 is a top view of an example configuration of an imaging pixel.

FIG. 6 is a cross-sectional view of the imaging pixel illustrated inFIG. 5.

FIG. 7 is a top view of an example configuration of phase differencedetection pixels.

FIG. 8 is a cross-sectional view of the phase difference detectionpixels illustrated in FIG. 7.

FIG. 9 illustrates the operation of an imaging pixel.

FIG. 10 illustrates the operation of a phase difference detection pixel.

FIG. 11 illustrates the operation of a phase difference detection pixel.

FIG. 12 is a top view of another example configuration (Modificationexample 1) of phase difference detection pixels.

FIG. 13 is a top view of still another example configuration(Modification example 2) of phase difference detection pixels.

FIG. 14 is a top view of still another example configuration(Modification example 3) of phase difference detection pixels.

FIG. 15 illustrates the operation of phase difference detection pixels.

FIG. 16 is a top view of still another example configuration(Modification example 4) of phase difference detection pixels.

FIG. 17 is a top view of still another example configuration(Modification example 5) of phase difference detection pixels.

FIG. 18 is a top view of still another example configuration(Modification example 5) of phase difference detection pixels.

FIG. 19 illustrates another example (Modification example 6) of thepixel arrangement of an image sensor.

FIG. 20 is a top view of still another example configuration(Modification example 6) of a phase difference detection pixel.

FIG. 21 is a top view of still another example configuration(modification of Modification example 6) of a phase difference detectionpixel.

FIG. 22 is a cross-sectional view of still another example configuration(Modification example 7) of a phase difference detection pixel.

FIG. 23 is a top view of still another example configuration(Modification example 8) of phase difference detection pixels.

FIG. 24 is a cross-sectional view of the phase difference detectionpixels illustrated in FIG. 23.

FIG. 25 is a top view of still another example configuration(Modification example 9) of phase difference detection pixels.

FIG. 26 is a top view of still another example configuration(Modification example 10) of phase difference detection pixels.

FIG. 27 is a top view of still another example configuration(Modification example 11) of phase difference detection pixels.

FIG. 28 is a top view of still another example configuration(Modification example 12) of phase difference detection pixels.

FIG. 29 is a top view of still another example configuration(Modification example 13) of phase difference detection pixels.

FIG. 30 is a top view of still another example configuration(Modification example 14) of phase difference detection pixels.

FIG. 31 is a top view of still another example configuration(Modification example 15) of phase difference detection pixels.

DESCRIPTION OF EMBODIMENT(S)

Hereinafter, an embodiment of the present technology will be describedwith reference to the drawings.

[Examples of Function and Configuration of Electronic Apparatus]

FIG. 1 is a block diagram illustrating an embodiment of an electronicapparatus including an image sensor to which the present technology isapplied.

An electronic apparatus 1 of FIG. 1, which is configured as a digitalcamera, a portable terminal with an imaging function, or the like,captures images of an object to generate captured images by an autofocus (AF) function, and records the captured images as still images ormoving images. The following description assumes that still images aremainly recorded.

The electronic apparatus 1 includes a lens unit 11, an operation unit12, a control unit 13, an image sensor 14, a signal processing unit 15,a storage unit 16, a display unit 17, a phase difference detection unit18, and a driving unit 19.

The lens unit 11 collects light (object light) from an object. Theobject light collected by the lens unit 11 enters the image sensor 14.

The lens unit 11 includes a zoom lens 21, a diaphragm 22, and a focuslens 23.

The zoom lens 21 changes a focal length by being driven by the drivingunit 19 to move in an optical axis direction, thereby adjusting themagnification of an object included in a captured image. The diaphragm22 changes the degree of aperture by being driven by the driving unit19, thereby adjusting the amount of object light that enters the imagesensor 14. The focus lens 23 is driven by the driving unit 19 to move inan optical axis direction, thereby adjusting focus.

The operation unit 12 receives an operation from a user. For example,when a shutter button (not illustrated) has been pushed, the operationunit 12 supplies an operation signal indicating the push to the controlunit 13.

The control unit 13 controls the operation of each component of theelectronic apparatus 1.

For example, when having received the operation signal indicating thepush of the shutter button, the control unit 13 supplies an instructionto record a still image to the signal processing unit 15. In the case ofdisplaying a live-view image, which is a real-time image of an object,on the display unit 17, the control unit 13 supplies an instruction togenerate a live-view image to the signal processing unit 15.

In the case of performing focusing determination by a phase differencedetection method, the control unit 13 supplies an instruction to carryout operation (phase difference detection operation) of performingfocusing determination to the signal processing unit 15. The phasedifference detection method detects a focus in the following manner:light that has passed through an imaging lens is subjected to pupildivision to form a pair of images, and the distance between the formedimages (the amount of deviation between the images) is measured (phasedifference is detected) so that the degree of focusing is detected.

The image sensor 14 is a solid-state imaging device thatphotoelectrically converts received object light to electrical signals.

For example, the image sensor 14 is implemented by a complementary metaloxide semiconductor (CMOS) image sensor, a charge coupled device (CCD)image sensor, or the like. In a pixel array unit of the image sensor 14are arranged, as a plurality of pixels, pixels (imaging pixels) thatgenerate signals for generating a captured image on the basis ofreceived object light and pixels (phase difference detection pixels)that generate signals for performing phase difference detection. Theimage sensor 14 supplies the electrical signals generated byphotoelectric conversion to the signal processing unit 15.

The signal processing unit 15 performs various kinds of signalprocessing on the electrical signals supplied from the image sensor 14.

For example, when the instruction to record a still image has beensupplied from the control unit 13, the signal processing unit 15generates data (still image data) of the still image, performs blacklevel correction, defect correction, shading correction, color mixturecorrection, and the like, and supplies the resulting data to the storageunit 16. When the instruction to generate a live-view image has beensupplied from the control unit 13, the signal processing unit 15generates data (live-view image data) of the live-view image on thebasis of output signals from the imaging pixels in the image sensor 14,performs black level correction, defect correction, shading correction,color mixture correction, and the like, and supplies the resulting datato the display unit 17.

When the instruction to carry out phase difference detection operationhas been supplied from the control unit 13, the signal processing unit15 generates data (phase difference detection data) for detecting phasedifference, on the basis of output signals from the phase differencedetection pixels in the image sensor 14, and supplies the data to thephase difference detection unit 18.

The storage unit 16 records image data supplied from the signalprocessing unit 15. The storage unit 16 is configured as, for example,one or more removable recording media, such as a disc (e.g., a digitalversatile disc (DVD)) and a semiconductor memory (e.g., a memory card).Such recording media may be incorporated in the electronic apparatus 1or may be detachable from the electronic apparatus 1.

The display unit 17 displays an image on the basis of image datasupplied from the signal processing unit 15. For example, when live-viewimage data has been supplied from the signal processing unit 15, thedisplay unit 17 displays a live-view image. The display unit 17 isimplemented by, for example, a liquid crystal display (LCD), an organicelectro-luminescence (EL) display, or the like.

The phase difference detection unit 18 calculates the amount (defocusamount) of focus deviation on the basis of phase difference detectiondata supplied from the signal processing unit 15, thereby determiningwhether focusing is obtained with respect to an object targeted forfocusing (focusing target). When an object in a focus area is focused,the phase difference detection unit 18 supplies, as a focusingdetermination result, information indicating that focusing is obtainedto the driving unit 19. When the focusing target is not focused, thephase difference detection unit 18 supplies, as a focusing determinationresult, information indicating the calculated defocus amount to thedriving unit 19.

The driving unit 19 drives the zoom lens 21, the diaphragm 22, and thefocus lens 23. For example, the driving unit 19 calculates the drivingamount of the focus lens 23 on the basis of the focusing determinationresult supplied from the phase difference detection unit 18, and movesthe focus lens 23 in accordance with the calculated driving amount.

Specifically, when focusing is obtained, the driving unit 19 keeps thefocus lens 23 at the current position. When focusing is not obtained,the driving unit 19 calculates the driving amount (movement distance) onthe basis of the focusing determination result indicating the defocusamount and the position of the focus lens 23, and moves the focus lens23 in accordance with the driving amount.

[Example Configuration of Image Sensor]

FIG. 2 is a block diagram illustrating an example configuration of theimage sensor 14.

The image sensor 14 includes a pixel array unit 111, a vertical drivingunit 112, a column processing unit 113, a horizontal driving unit 114,and a system control unit 115. The pixel array unit 111, the verticaldriving unit 112, the column processing unit 113, the horizontal drivingunit 114, and the system control unit 115 are formed on a semiconductorsubstrate (chip) (not illustrated).

In the pixel array unit 111, the above-described imaging pixels andphase difference detection pixels are two-dimensionally arranged in amatrix. In the following description, the imaging pixels and the phasedifference detection pixels are also simply called “pixels”.

Furthermore, pixel driving lines 116 are formed in the respective rowsalong the left-right direction of the figure (the array direction of thepixels of the pixel rows) and vertical signal lines 117 are formed inthe respective columns along the up-down direction of the figure (thearray direction of the pixels of the pixel columns) for the pixel arrayin a matrix in the pixel array unit 111. One terminal of the pixeldriving line 116 is connected to an output terminal corresponding toeach row of the vertical driving unit 112.

The vertical driving unit 112 includes a shift register, an addressdecoder, or the like, and is a pixel driving unit that drives the pixelsin the pixel array unit 111 simultaneously for all the pixels, in unitsof rows, or the like by driving signals. Although a specificconfiguration of the vertical driving unit 112 is not illustrated, thevertical driving unit 112 includes two scanning systems, a read scanningsystem and a sweep scanning system.

The read scanning system selectively scans the pixels in the pixel arrayunit 111 sequentially in units of rows to read signals from the pixels.In row driving (rolling shutter operation), as for sweeping, sweepscanning is performed on the read row to be subjected to read scanningby the read scanning system, earlier than the read scanning by a periodof time corresponding to a shutter speed. In global exposure (globalshutter operation), collective sweeping is performed earlier thancollective transfer by a period of time corresponding to a shutterspeed.

This sweeping sweeps (resets) unnecessary charge from photoelectricconversion elements of the pixels of the read row. By sweeping(resetting) unnecessary charge, so-called electronic shutter operationis performed. Here, electronic shutter operation refers to operation ofdiscarding charge of photoelectric conversion elements and newlystarting exposure (starting accumulation of charge).

Signals read by the reading operation by the read scanning systemcorrespond to the amount of light that has entered after the previousreading operation or electronic shutter operation. In row driving, aperiod from the previous read timing by reading operation or sweeptiming by electronic shutter operation to the present read timing byreading operation serves as accumulation time of charge (an exposureperiod) in the pixels. In global exposure, a period from collectivesweeping to collective transfer serves as accumulation time (an exposureperiod).

Pixels signals output from the pixels of the pixel row selectivelyscanned by the vertical driving unit 112 are supplied to the columnprocessing unit 113 through the respective vertical signal lines 117.The column processing unit 113 performs predetermined signal processingon the pixel signal output from the pixel of the selected row throughthe vertical signal line 117 for each pixel column of the pixel arrayunit 111, and temporarily retains or supplies, to the signal processingunit 15 (FIG. 1), the pixel signals after the signal processing.

Specifically, the column processing unit 113 performs at least denoisingprocessing, for example, correlated double sampling (CDS) processing, asthe signal processing. This CDS processing by the column processing unit113 removes reset noise and pixel-specific fixed pattern noise, such asthreshold variation of amplifier transistors. In addition to thedenoising processing, the column processing unit 113 may have ananalog/digital (A/D) conversion function, for example, and outputsignals levels by digital signals.

The horizontal driving unit 114 includes a shift register, an addressdecoder, or the like, and sequentially selects unit circuitscorresponding to the pixel columns of the column processing unit 113. Bythis selective scanning by the horizontal driving unit 114, the pixelsignals having been subjected to the signal processing by the columnprocessing unit 113 are sequentially output to a signal processing unit118.

The system control unit 115 includes a timing generator, which generatesvarious timing signals, or the like, and performs driving control of thevertical driving unit 112, the column processing unit 113, thehorizontal driving unit 114, and the like on the basis of the varioustiming signals generated by the timing generator.

[Pixel Arrangement of Pixel Array Unit]

Next, the pixel arrangement of the pixel array unit 111 is describedwith reference to FIG. 3.

In FIG. 3, a direction from left toward right (row direction) is calledX direction, a direction from bottom toward top (column direction) iscalled Y direction, and a direction from rear to front is called Zdirection.

As illustrated in FIG. 3, in the pixel array unit 111, a plurality ofimaging pixels 121 are two-dimensionally arranged in a matrix on an XYplane. The imaging pixels 121 include R pixels, G pixels, and B pixels,which are regularly arranged in a Bayer array.

In addition, in the pixel array unit 111, a plurality of phasedifference detection pixels 122 are arranged among the plurality ofimaging pixels 121 two-dimensionally arranged in a matrix. Specifically,the phase difference detection pixels 122 include an A pixel whoselight-receiving region is shielded from light on the right side in the Xdirection and a B pixel whose light-receiving region is shielded fromlight on the left side in the X direction. These pixels replace part ofthe imaging pixels 121 in a predetermined row among the pixel rows inthe pixel array unit 111 to be regularly arranged in a specific pattern(in FIG. 3, the A pixels and the B pixels are arranged alternately).

Note that the arrangement of the imaging pixels 121 and the phasedifference detection pixels 122 in the pixel array unit 111 is notlimited to the arrangement illustrated in FIG. 3, and arrangement inanother pattern may be adopted. For example, the A pixels and the Bpixels may be arranged in a width of two rows of the pixel array unit111. Alternatively, the phase difference detection pixels 122 mayinclude an A pixel whose light-receiving region is shielded from lighton the upper side in the Y direction and a B pixel whose light-receivingregion is shielded from light on the lower side in the Y direction, andthose pixels may be arranged in the Y direction (column direction).

[Imaging Processing of Electronic Apparatus]

Here, imaging processing by the electronic apparatus 1 is described withreference to the flowchart of FIG. 4.

The imaging processing of FIG. 4 starts when a power switch of theelectronic apparatus 1 is turned on. At this time, a live-view image,luminance information obtained by photometry by a photometry unit (notillustrated), or the like is displayed on the display unit 17.

In step S11 the signal processing unit 15 reads pixel data (outputsignals) of the phase difference detection pixels 122 from the imagesensor 14. At this time, pixel data of the A pixels and pixel data ofthe B pixels of the phase difference detection pixels 122 may be readsimultaneously or may be read at different timings. The signalprocessing unit 15 generates phase difference detection data on thebasis of the read output signals, and supplies the phase differencedetection data to the phase difference detection unit 18.

In step S12, the phase difference detection unit 18 calculates a defocusamount on the basis of the phase difference detection data supplied fromthe signal processing unit 15.

In step S13, the phase difference detection unit 18 determines whetherthe absolute value of the calculated defocus amount is smaller than apredetermined value, thereby determining whether focusing is obtainedwith respect to a focusing target.

When it is determined that focusing is not obtained in step S13, thephase difference detection unit 18 supplies, as a focusing determinationresult, information indicating the calculated defocus amount to thedriving unit 19, and the processing proceeds to step S14.

In step S14, the driving unit 19 calculates a driving amount (movementdistance) on the basis of the focusing determination result indicatingthe defocus amount and the current position of the focus lens 23, andmoves the focus lens 23 in accordance with the driving amount. Then, theprocessing returns to step S11, and the subsequent processing isrepeated.

When it is determined that focusing is obtained in step S13, the phasedifference detection unit 18 supplies, as a focusing determinationresult, information indicating that focusing is obtained to the drivingunit 19, and the processing proceeds to step S15. At this time, thedriving unit 19 keeps the focus lens 23 at the current position.

In step S15, the operation unit 12 determines whether the shutter buttonhas been operated. When it is determined that the shutter button has notbeen operated in step S15, the processing returns to step S11, and thesubsequent processing is repeated.

When it is determined that the shutter button has been operated in stepS15, the processing proceeds to step S16, and the signal processing unit15 reads pixel data (output signals) of all the pixels from the imagesensor 14. At this time, at least the pixel data of the imaging pixels121 is read row by row after the accumulation and retention of chargeare performed simultaneously. Then, the signal processing unit 15generates still image data on the basis of the read output signals,performs black level correction, defect correction, shading correction,color mixture correction, and the like, and, in step S17, stores theresulting data in the storage unit 16.

The above processing makes it possible to obtain an image that hassimultaneity maintained owing to a global shutter function and is freefrom defocus owing to a phase difference AF function.

The configuration and operation of the imaging pixels 121 and the phasedifference detection pixels 122 in the pixel array unit 111, which allowthe global shutter function and the phase difference AF function to beboth implemented as described above, are detailed below.

[Example Configuration of Imaging Pixel]

First, an example configuration of the imaging pixel 121 is describedwith reference to FIGS. 5 and 6. FIG. 5 is a top view of the imagingpixel 121, and FIG. 6 is a cross-sectional view of the imaging pixel 121along the broken line a-a′ of the right side of FIG. 5.

As illustrated on the left side of FIG. 5, the imaging pixel 121includes a photodiode (PD) 201, a memory unit (MEM) 202, a firsttransfer gate 203, a floating diffusion region (FD) 204, a secondtransfer gate 205, a reset transistor 206, an amplifier transistor 207,a selection transistor 208, and a charge discharging unit 209.

The photodiode 201 is formed in the following manner, for example: in aP-type well layer formed in an N-type substrate, an N-type buried layeris buried with a P-type layer formed on the substrate surface side.

The memory unit 202 is formed as a charge accumulation unit of thepresent technology, and functions as a charge retention unit thatretains charge. The photodiode 201 and the memory unit 202 are formedside by side in the X direction (row direction).

The first transfer gate 203 includes a gate electrode made ofpolysilicon and an insulating film. The first transfer gate 203 isformed to cover a space between the photodiode 201 and the memory unit202 and an upper portion of the memory unit 202 with the insulating filmlocated therebetween, and transfers charge accumulated in the photodiode201 to the memory unit 202 by application of a driving signal TRX to thegate electrode via a contact (not illustrated).

The second transfer gate 205 includes a gate electrode made ofpolysilicon and an insulating film. The second transfer gate 205 isformed to cover a space between the memory unit 202 and the floatingdiffusion region 204 with the insulating film located therebetween, andtransfers charge accumulated in the memory unit 202 to the floatingdiffusion region 204 by application of a driving signal TRG to the gateelectrode via a contact (not illustrated).

The reset transistor 206 is connected between a power source (notillustrated) and the floating diffusion region 204, and resets thefloating diffusion region 204 by application of a driving signal RST toa gate electrode.

The amplifier transistor 207, whose drain electrode is connected to thepower source (not illustrated) and whose gate electrode is connected tothe floating diffusion region 204, reads the voltage of the floatingdiffusion region 204.

The selection transistor 208, whose drain electrode is connected to asource electrode of the amplifier transistor 207 and whose sourceelectrode is connected to a vertical signal line 116 (FIG. 2), forexample, selects a pixel from which a pixel signal is to be read byapplication of a driving signal SEL to a gate electrode.

The charge discharging unit 209 discharges charge accumulated in thephotodiode 201 to a drain of an N-type layer by application of a drivingsignal OFG to a gate electrode at the time of exposure start.

In addition, as illustrated on the right side of FIG. 5, the imagingpixel 121 includes a light-shielding film 210 made of tungsten (W), forexample. The light-shielding film 210 is formed to shield the memoryunit 202 from light. The light-shielding film 210 is provided with anopening 211 for allowing the photodiode 201 to receive light (objectlight) and an opening 212 for connecting the gate electrodes of thesecond transfer gate 205 to the charge discharging unit 209 to wiring214 (FIG. 6) with contacts.

Furthermore, the imaging pixel 121 includes an on-chip lens 213 in theuppermost layer. The on-chip lens 213 is formed such that its opticalaxis coincides with the center of the opening 211 (a light-receivingregion of the photodiode 201).

Note that, as illustrated in FIG. 6, a color filter 215 having spectralproperties corresponding to an R pixel, a G pixel, or a B pixel isformed below the on-chip lens 213 in the imaging pixel 121.

[Example Configuration of Phase Difference Detection Pixel]

Next, an example configuration of the phase difference detection pixel122 is described with reference to FIGS. 7 and 8. FIG. 7 shows top viewsof the phase difference detection pixel 122A (A pixel) whose right sideis shielded from light and the phase difference detection pixel 122B (Bpixel) whose left side is shielded from light among the phase differencedetection pixels 122. FIG. 8 shows cross-sectional views of the phasedifference detection pixels 122A and 122B along the broken lines a-a′and b-b′ of FIG. 7.

Note that description is omitted regarding parts of the phase differencedetection pixels 122A and 122B illustrated in FIGS. 7 and 8 and theimaging pixel 121 described with reference to FIGS. 5 and 6 that areformed in a similar manner.

In the phase difference detection pixel 122A, the light-shielding film210 is formed to shield the memory unit 202 from light and is providedwith an opening 221A for allowing the photodiode 201 to receive light.In the phase difference detection pixel 122B, the light-shielding film210 is formed to shield the photodiode 201 from light and is providedwith an opening 221B for allowing the memory unit 202 to receive light.

The opening 221A and the opening 221B preferably have the same shape.

An on-chip lens 222 is formed in the same position in each of the phasedifference detection pixels 122A and 122B. Specifically, in the phasedifference detection pixels 122A and 122B, the on-chip lenses 222 areformed in positions where the distance between an optical axis of theon-chip lens 222 and a side of the opening 221A on the right side (thememory unit 202 side) in the phase difference detection pixel 122Abecomes equal to the distance between an optical axis of the on-chiplens 222 and a side of the opening 221B on the left side (the photodiode201 side) in the phase difference detection pixel 122B.

That is, in the pair of phase difference detection pixels 122 (122A and122B), the openings 221A and 221B of the light-shielding film 210 areprovided in positions symmetrical to each other in the X direction inwhich the phase difference detection pixels 122A and 122B are arrayed,with respect to the optical axes of the on-chip lenses 222.

Note that the position of the on-chip lens 222 in the phase differencedetection pixel 122 is different from the position of the on-chip lens213 in the imaging pixel 121; however, the size of the on-chip lens 222in the phase difference detection pixel 122 is preferably the same asthe size of the on-chip lens 213 in the imaging pixel 121.

As illustrated in FIG. 8, a color filter is not formed below the on-chiplens 222 in the phase difference detection pixel 122.

With the above structure, it is possible to improve the precision ofphase difference detection while suppressing deterioration of resolutionin a solid-state imaging device 1 having the global shutter function andthe phase difference AF function, because the area of thelight-receiving region of the phase difference detection pixel is notreduced and the number of effective pixels of the whole solid-stateimaging device need not be reduced.

Next, the operation of the imaging pixel 121 and the phase differencedetection pixels 122A and 122B is described.

[Operation of Imaging Pixel]

First, the operation of the imaging pixel 121 is described withreference to FIG. 9. The operation (driving) of the imaging pixel 121described with reference to FIG. 9 is performed when a captured image isgenerated.

The upper stage of FIG. 9 shows a timing chart of driving signalsapplied to the selection transistor 208, the reset transistor 206, thefirst transfer gate 203, the second transfer gate 205, and the chargedischarging unit 209 of the imaging pixel 121.

The lower stage of FIG. 9 shows potential diagrams of the imaging pixel121 at times t1 to t4 in the timing chart in the upper stage of FIG. 9.

At time t1, charge corresponding to incident light amount is accumulatedin the photodiode (PD) 201 in all the imaging pixels 121.

After that, in a state where all the driving signals are off, thedriving signal RST is turned on, and the driving signal TRG is turnedon. Then, at time t2, when the driving signal TRX is turned on, chargeaccumulated in the photodiode 201 is transferred to the memory unit(MEM) 202.

After that, the driving signal TRX is turned off, so that charge isretained in the memory unit 202. Then, the driving signal RST is turnedoff and the driving signal OFG is turned on. As illustrated in thetiming chart in the upper stage of FIG. 9, a period during which thedriving signal OFG is off is accumulation time T in the imaging pixel121.

At time t3, when the driving signals SEL and RST are turned on, thephotodiode 201 is brought into a state where no charge is accumulatedtherein.

At time t4, when the driving signal TRG is turned on, charge retained inthe memory unit 202 is transferred to the floating diffusion region (FD)204.

The above operation makes it possible to perform, in generating acaptured image, accumulation of charge in all the imaging pixels 121simultaneously and thus allows implementation of the global shutterfunction.

[Operation of Phase Difference Detection Pixel (A Pixel)]

Next, the operation of the phase difference detection pixel 122A (Apixel) is described with reference to FIG. 10. The operation (driving)of the phase difference detection pixel 122A described with reference toFIG. 10 is performed when a captured image is generated and alsoperformed when phase difference is detected.

The upper stage of FIG. 10 shows a timing chart of driving signalsapplied to the selection transistor 208, the reset transistor 206, thefirst transfer gate 203, the second transfer gate 205, and the chargedischarging unit 209 of the phase difference detection pixel 122A.

The lower stage of FIG. 10 shows potential diagrams of the phasedifference detection pixel 122A at times t11 to t14 in the timing chartin the upper stage of FIG. 10.

The operation of the phase difference detection pixel 122A illustratedin FIG. 10 is similar to the operation of the imaging pixel 121described with reference to FIG. 9 and description thereof is omitted.

Note that accumulation time Ta in the phase difference detection pixel122A illustrated in the timing chart in the upper stage of FIG. 10 maybe the same as or different from the accumulation time T in the imagingpixel 121 illustrated in the timing chart in the upper stage of FIG. 9.

[Operation of Phase Difference Detection Pixel (B pixel)]

Next, the operation of the phase difference detection pixel 122B (Bpixel) is described with reference to FIG. 11. The operation (driving)of the phase difference detection pixel 122B described with reference toFIG. 11 also is performed when a captured image is generated and alsoperformed when phase difference is detected.

The upper stage of FIG. 11 shows a timing chart of driving signalsapplied to the selection transistor 208, the reset transistor 206, thefirst transfer gate 203, the second transfer gate 205, and the chargedischarging unit 209 of the phase difference detection pixel 122B.

The lower stage of FIG. 11 shows potential diagrams of the phasedifference detection pixel 122B at times t21 to t24 in the timing chartin the upper stage of FIG. 11.

In a state where the driving signal OFG is always on, at time t21,charge corresponding to incident light amount is accumulated in thememory unit (MEM) 202. Because the driving signal OFG is always on,charge is not accumulated in the photodiode (PD) 201.

After that, when the driving signal RST is turned on and the drivingsignal TRG is turned on, charge accumulated in the memory unit 202 isreset.

At time t22, charge corresponding to incident light amount after thereset is accumulated in the memory unit 202.

After the driving signal RST is turned off, at time t23, when thedriving signals SEL and RST are turned on, the floating diffusion region(FD) 204 is reset.

At time t24, when the driving signal TRG is turned on, chargeaccumulated in the memory unit 202 is transferred to the floatingdiffusion region 204. As illustrated in the timing chart in the upperstage of FIG. 11, a period between when the driving signal TRG is turnedon to reset the memory unit 202 and when the driving signal TRG isturned on at time t24 is accumulation time Tb in the phase differencedetection pixel 122B.

Note that times t21 to t24 in FIG. 11 can be the same as times t11 tot14 in FIG. 10, respectively.

The above operation makes it possible to perform, in performing phasedifference detection, reading from the phase difference detection pixel122A and reading from the phase difference detection pixel 122Bsimultaneously and thus allows implementation of the phase difference AFfunction while maintaining the simultaneity of the phase differencedetection pixel 122A and the phase difference detection pixel 122B.

The accumulation time Ta in the phase difference detection pixel 122Aand the accumulation time Tb in the phase difference detection pixel122B can be set individually, and are preferably optimized depending onthe sensitivity (output) of the respective pixels. Specifically, eachaccumulation time is set so that the product of the sensitivity of thephase difference detection pixel 122A and the accumulation time Tabecomes equal to the product of the sensitivity of the phase differencedetection pixel 122B and the accumulation time Tb, that is, so that (thesensitivity of the phase difference detection pixel 122A)×(theaccumulation time Ta)=(the sensitivity of the phase difference detectionpixel 122B)×(the accumulation time Tb) is satisfied.

In this manner, signals used for phase difference detection can be madeuniform in each of the pair of phase difference detection pixels and theprecision of phase difference detection can be improved.

Hereinafter, modification examples of phase difference detection pixelswill be described.

MODIFICATION EXAMPLE 1

[Example Configuration of Phase Difference Detection Pixel]

FIG. 12 illustrates another example configuration of the phasedifference detection pixel 122.

Note that description is omitted regarding parts of the phase differencedetection pixels 122A and 122B illustrated in FIG. 12 and the phasedifference detection pixels 122A and 122B illustrated in FIG. 7 that areformed in a similar manner.

As illustrated in FIG. 12, in the phase difference detection pixel 122A,approximately half of the photodiode 201 on the left side is providedwith the opening 221A. In the phase difference detection pixel 122B,approximately half of the photodiode 201 on the right side is providedwith the opening 221B.

Furthermore, as illustrated in FIG. 12, the openings 221A and 221B areformed so as to be long as possible in the Y direction. Specifically,the lengths of the openings 221A and 221B in the Y direction are setlonger than the length of the opening 211 (FIG. 5) of the imaging pixel121 in the Y direction.

The opening 221A and the opening 221B preferably have the same shape.

The on-chip lens 222 is formed in the same position in each of the phasedifference detection pixels 122A and 122B. Specifically, in the phasedifference detection pixels 122A and 122B, the on-chip lenses 222 areformed in positions where the distance between an optical axis of theon-chip lens 222 and a side of the opening 221A on the right side (thememory unit 202 side) in the phase difference detection pixel 122Abecomes equal to the distance between an optical axis of the on-chiplens 222 and a side of the opening 221B on the left side (the photodiode201 side) in the phase difference detection pixel 122B.

That is, in the pair of phase difference detection pixels 122A and 122B,the openings 221A and 221B of the light-shielding film 210 are providedin positions symmetrical to each other in the X direction in which thephase difference detection pixels 122A and 122B are arrayed, withrespect to the optical axes of the on-chip lenses 222.

In each of the phase difference detection pixels 122A and 122B of FIG.12, the on-chip lens 222 is formed such that its optical axis coincideswith the center of the light-receiving region of the photodiode 201.That is, the positions of the on-chip lenses 222 in the phase differencedetection pixels 122A and 122B of FIG. 12 are the same as the positionof the on-chip lens 213 in the imaging pixel 121.

Also with the above structure, it is possible to improve the precisionof phase difference detection while suppressing deterioration ofresolution in a solid-state imaging device 1 having the global shutterfunction and the phase difference AF function, because the area of thelight-receiving region of the phase difference detection pixel is notreduced and the number of effective pixels of the whole solid-stateimaging device need not be reduced.

Note that the operation of each of the phase difference detection pixels122A and 122B illustrated in FIG. 12 is similar to that described withreference to FIG. 10.

MODIFICATION EXAMPLE 2

[Example Configuration of Phase Difference Detection Pixel]

FIG. 13 illustrates still another example configuration of the phasedifference detection pixel 122.

Note that description is omitted regarding parts of the phase differencedetection pixels 122A and 122B illustrated in FIG. 13 and the phasedifference detection pixels 122A and 122B illustrated in FIG. 7 that areformed in a similar manner.

In the phase difference detection pixels 122A and 122B illustrated inFIG. 13, the photodiodes 201 and the memory units 202 are formed inpositions symmetrical to each other in the X direction. Specifically,while the photodiode 201 is formed on the left side and the memory unit202 is formed on the right side in the phase difference detection pixel122A, the memory unit 202 is formed on the left side and the photodiode201 is formed on the right side in the phase difference detection pixel122B.

As illustrated in FIG. 13, the phase difference detection pixel 122A isprovided with the opening 221A for allowing the photodiode 201, which isformed on the left side of the phase difference detection pixel 122A, toreceive light. The phase difference detection pixel 122B is providedwith the opening 221B for allowing the photodiode 201, which is formedon the right side of the phase difference detection pixel 122B, toreceive light.

The opening 221A and the opening 221B preferably have the same shape.

The on-chip lens 222 is formed in the same position in each of the phasedifference detection pixels 122A and 122B. Specifically, in the phasedifference detection pixels 122A and 122B, the on-chip lenses 222 areformed in positions where the distance between an optical axis of theon-chip lens 222 and a side of the opening 221A on the right side (thememory unit 202 side) in the phase difference detection pixel 122Abecomes equal to the distance between an optical axis of the on-chiplens 222 and a side of the opening 221B on the left side (the memoryunit 202 side) in the phase difference detection pixel 122B.

That is, in the pair of phase difference detection pixels 122A and 122B,the openings 221A and 221B of the light-shielding film 210 are providedin positions symmetrical to each other in the X direction in which thephase difference detection pixels 122A and 122B are arrayed, withrespect to the optical axes of the on-chip lenses 222.

Also with the above structure, it is possible to improve the precisionof phase difference detection while suppressing deterioration ofresolution in a solid-state imaging device 1 having the global shutterfunction and the phase difference AF function, because the area of thelight-receiving region of the phase difference detection pixel is notreduced and the number of effective pixels of the whole solid-stateimaging device need not be reduced.

Note that the operation of the phase difference detection pixels 122Aand 122B illustrated in FIG. 13 is similar to that described withreference to FIG. 10.

MODIFICATION EXAMPLE 3

[Example Configuration of Phase Difference Detection Pixel]

FIG. 14 illustrates still another example configuration of the phasedifference detection pixel 122.

Note that description is omitted regarding parts of the phase differencedetection pixels 122A and 122B illustrated in FIG. 14 and the phasedifference detection pixels 122A and 122B illustrated in FIG. 7 that areformed in a similar manner.

In each of the phase difference detection pixels 122A and 122Billustrated in FIG. 14, the photodiode 201, the memory unit 202, and thelike are formed to be in a state obtained by rotating the phasedifference detection pixels 122A and 122B illustrated in FIG. 7 leftwardby 90 degrees. That is, in the phase difference detection pixels 122Aand 122B, the photodiode 201 and the memory unit 202 are formed side byside in the Y direction.

Note that in this example, also in the imaging pixel 121, the photodiode201, the memory unit 202, and the opening 211 in the light-shieldingfilm 210 are formed to be in a state obtained by rotating the imagingpixel 121 illustrated in FIG. 5 leftward by 90 degrees.

As illustrated in FIG. 14, in the phase difference detection pixel 122A,approximately half of each of the photodiode 201 and the memory unit 202on the left side is provided with the opening 221A. In the phasedifference detection pixel 122B, approximately half of each of thephotodiode 201 and the memory unit 202 on the right side is providedwith the opening 221B.

Furthermore, as illustrated in FIG. 14, the openings 221A and 221B areformed so as to be long as possible in the Y direction.

The opening 221A and the opening 221B preferably have the same shape.

The on-chip lens 222 is formed in the same position in each of the phasedifference detection pixels 122A and 122B. Specifically, in the phasedifference detection pixels 122A and 122B, the on-chip lenses 222 areformed in positions where the distance between an optical axis of theon-chip lens 222 and a side of the opening 221A on the right side in thephase difference detection pixel 122A becomes equal to the distancebetween an optical axis of the on-chip lens 222 and a side of theopening 221B on the left side in the phase difference detection pixel122B.

That is, in the pair of phase difference detection pixels 122A and 122B,the openings 221A and 221B of the light-shielding film 210 are providedin positions symmetrical to each other in the X direction in which thephase difference detection pixels 122A and 122B are arrayed, withrespect to the optical axes of the on-chip lenses 222.

In each of the phase difference detection pixels 122A and 122B of FIG.14, the on-chip lens 222 is formed such that its optical axis coincideswith the center of the light-receiving region of the photodiode 201.That is, the positions of the on-chip lenses 222 in the phase differencedetection pixels 122A and 122B of FIG. 14 are the same as the positionof the on-chip lens 213 in the imaging pixel 121.

Also with the above structure, it is possible to improve the precisionof phase difference detection while suppressing deterioration ofresolution in a solid-state imaging device 1 having the global shutterfunction and the phase difference AF function, because the area of thelight-receiving region of the phase difference detection pixel is notreduced and the number of effective pixels of the whole solid-stateimaging device need not be reduced.

Here, the operation of the imaging pixel 121 and the phase differencedetection pixels 122A and 122B in this example is described. The drivingof the imaging pixel 121 is similar to that described with reference toFIG. 9 and description thereof is omitted.

[Operation of Phase Difference Detection Pixel]

Next, the operation of the phase difference detection pixels 122A and122B is described with reference to FIG. 15. In this example, the phasedifference detection pixels 122A and 122B perform the same operation.

The upper stage of FIG. 15 shows a timing chart of driving signalsapplied to the selection transistor 208, the reset transistor 206, thefirst transfer gate 203, the second transfer gate 205, and the chargedischarging unit 209 of the phase difference detection pixel 122 (122Aand 122B).

The lower stage of FIG. 15 shows potential diagrams of the phasedifference detection pixel 122 at times t31 to t34 in the timing chartin the upper stage of FIG. 15.

At time t31, charge corresponding to incident light amount isaccumulated in each of the photodiode (PD) 201 and the memory unit (MEM)202 in all the phase difference detection pixels 122.

After that, in a state where all the driving signals are off, thedriving signal RST is turned on. Then, at time t32, when the drivingsignal TRX is turned on, charge accumulated in the photodiode 201 istransferred to the memory unit 202.

Note that since the driving signal TRG is not turned on between time t31and time t32, charge of the memory unit 202 is not reset, and chargeaccumulated in the photodiode 201 and charge accumulated in the memoryunit 202 are combined at time t32.

After that, the driving signal TRX is turned off, so that charge isretained in the memory unit 202. Then, the driving signal RST is turnedoff and the driving signal OFG is turned on. As illustrated in thetiming chart in the upper stage of FIG. 15, a period during which thedriving signal OFG is off is accumulation time in the phase differencedetection pixel 122 of this example.

At time t33, when the driving signals SEL and RST are turned on, thephotodiode 201 is brought into a state where no charge is accumulatedtherein.

At time t34, when the driving signal TRG is turned on, charge retainedin the memory unit 202 is transferred to the floating diffusion region(FD) 204.

In this manner, in the phase difference detection pixel 122A, chargeaccumulated in the photodiode 201 and the memory unit 202, which areshielded from light on the right side, is read together, and in thephase difference detection pixel 122B, charge accumulated in thephotodiode 201 and the memory unit 202, which are shielded from light onthe left side, is read together.

The above operation also makes it possible to perform, in performingphase difference detection, reading from the phase difference detectionpixel 122A and reading from the phase difference detection pixel 122Bsimultaneously and thus allows implementation of the phase difference AFfunction while maintaining the simultaneity of the phase differencedetection pixel 122A and the phase difference detection pixel 122B.

MODIFICATION EXAMPLE 4

[Example Configuration of Phase Difference Detection Pixel]

FIG. 16 illustrates still another example configuration of the phasedifference detection pixel 122.

Note that description is omitted regarding parts of the phase differencedetection pixels 122A and 122B illustrated in FIG. 16 and the phasedifference detection pixels 122A and 122B illustrated in FIG. 7 that areformed in a similar manner.

In each of the phase difference detection pixels 122A and 122Billustrated in FIG. 16, the photodiode 201, the memory unit 202, and thelike are formed to be in a state obtained by rotating the phasedifference detection pixels 122A and 122B illustrated in FIG. 7 leftwardby 90 degrees. That is, in the phase difference detection pixels 122Aand 122B, the photodiode 201 and the memory unit 202 are formed side byside in the Y direction.

Note that in this example, also in the imaging pixel 121, the photodiode201, the memory unit 202, and the opening 211 in the light-shieldingfilm 210 are formed to be in a state obtained by rotating the imagingpixel 121 illustrated in FIG. 5 leftward by 90 degrees.

As illustrated in FIG. 16, in the phase difference detection pixel 122A,approximately half of the photodiode 201 on the left side is providedwith the opening 221A. In the phase difference detection pixel 122B,approximately half of the photodiode 201 on the right side is providedwith the opening 221B.

Furthermore, as illustrated in FIG. 16, the openings 221A and 221B areformed so as to be long as possible in the X direction and the Ydirection. Specifically, the lengths of the openings 221A and 221B inthe X direction are set longer than half the length of the opening 211of the imaging pixel 121 in the X direction, and the lengths of theopenings 221A and 221B in the Y direction are set longer than the lengthof the opening 211 of the imaging pixel 121 in the Y direction.

The on-chip lens 222 is formed in the same position in each of the phasedifference detection pixels 122A and 122B. Specifically, in the phasedifference detection pixels 122A and 122B, the on-chip lenses 222 areformed in positions where the distance between an optical axis of theon-chip lens 222 and a side of the opening 221A on the right side in thephase difference detection pixel 122A becomes equal to the distancebetween an optical axis of the on-chip lens 222 and a side of theopening 221B on the left side in the phase difference detection pixel122B.

That is, in the pair of phase difference detection pixels 122A and 122B,the openings 221A and 221B of the light-shielding film 210 are providedin positions symmetrical to each other in the X direction in which thephase difference detection pixels 122A and 122B are arrayed, withrespect to the optical axes of the on-chip lenses 222.

In each of the phase difference detection pixels 122A and 122B of FIG.16, the on-chip lens 222 is formed such that its optical axis coincideswith the center of the light-receiving region of the photodiode 201.That is, the positions of the on-chip lenses 222 in the phase differencedetection pixels 122A and 122B of FIG. 16 are the same as the positionof the on-chip lens 213 in the imaging pixel 121.

Also with the above structure, it is possible to improve the precisionof phase difference detection while suppressing deterioration ofresolution in a solid-state imaging device 1 having the global shutterfunction and the phase difference AF function, because the area of thelight-receiving region of the phase difference detection pixel is notreduced and the number of effective pixels of the whole solid-stateimaging device need not be reduced.

Note that the operation of each of the phase difference detection pixels122A and 122B illustrated in FIG. 16 is similar to that described withreference to FIG. 10.

MODIFICATION EXAMPLE 5

[Example Configuration of Phase Difference Detection Pixel]

FIGS. 17 and 18 illustrate another example configuration of the phasedifference detection pixel 122.

Note that description is omitted regarding parts of the phase differencedetection pixel 122 (122A and 122B) illustrated in FIGS. 17 and 18 andthe phase difference detection pixels 122A and 122B illustrated in FIG.7 that are formed in a similar manner.

The phase difference detection pixel 122 of FIG. 17 differs from thephase difference detection pixels 122A and 122B of FIG. 7 in that aphotodiode 231 is provided instead of the memory unit 202. Thephotodiode 231 is formed as a charge accumulation unit of the presenttechnology, and functions as a photoelectric conversion unit thataccumulates charge corresponding to incident light amount. Asillustrated in FIG. 17, the photodiode 201 and the photodiode 231 areformed side by side in the X direction (row direction).

As described above, the phase difference detection pixel 122 does notinclude the memory unit 202 and therefore does not perform globalshutter operation in this example. Note that the imaging pixel 121 hasthe configuration illustrated in FIG. 5 and includes the memory unit202, therefore being able to perform global shutter operation.

As illustrated in FIG. 18, the phase difference detection pixel 122A isprovided with the opening 221A for allowing the photodiode 201, which isplaced on the left side, to receive light. The phase differencedetection pixel 122B is provided with the opening 221B for allowing thephotodiode 231, which is placed on the right side, to receive light.

The opening 221A and the opening 221B preferably have the same shape.

The on-chip lens 222 is formed in the same position in each of the phasedifference detection pixels 122A and 122B. Specifically, in the phasedifference detection pixels 122A and 122B, the on-chip lenses 222 areformed in positions where the distance between an optical axis of theon-chip lens 222 and a side of the opening 221A on the right side (thephotodiode 231 side) in the phase difference detection pixel 122Abecomes equal to the distance between an optical axis of the on-chiplens 222 and a side of the opening 221B on the left side (the photodiode201 side) in the phase difference detection pixel 122B.

That is, in the pair of phase difference detection pixels 122A and 122B,the openings 221A and 221B of the light-shielding film 210 are providedin positions symmetrical to each other in the X direction in which thephase difference detection pixels 122A and 122B are arrayed, withrespect to the optical axes of the on-chip lenses 222.

Also with the above structure, it is possible to improve the precisionof phase difference detection while suppressing deterioration ofresolution in a solid-state imaging device 1 having the global shutterfunction and the phase difference AF function, because the area of thelight-receiving region of the phase difference detection pixel is notreduced and the number of effective pixels of the whole solid-stateimaging device need not be reduced.

Note that as described above, the phase difference detection pixels 122Aand 122B illustrated in FIG. 18 do not perform global shutter operation.Therefore, as their operation, rolling shutter operation of sequentiallyreading charge row by row or pixel by pixel is performed.

The above describes configurations in which phase difference detectionis performed on the basis of output signals of each of the pair of phasedifference detection pixels. The following describes a configuration inwhich one phase difference detection pixel has a function of a pair ofphase difference detection pixels.

MODIFICATION EXAMPLE 6

[Pixel Arrangement of Pixel Array Unit]

First, the pixel arrangement of the pixel array unit 111 of this exampleis described with reference to FIG. 19.

As illustrated in FIG. 19, in the pixel array unit 111, a plurality ofimaging pixels 121 are two-dimensionally arranged in a matrix on an XYplane. The imaging pixels 121 include R pixels, G pixels, and B pixels,which are regularly arranged in a Bayer array.

In addition, in the pixel array unit 111, a plurality of phasedifference detection pixels 311 are arranged among the plurality ofimaging pixels 121 two-dimensionally arranged in a matrix. Specifically,the phase difference detection pixels 311 include AB pixels having afunction of two pixels of an A pixel whose light-receiving region isshielded from light on the right side in the X direction and a B pixelwhose light-receiving region is shielded from light on the left side inthe X direction. These pixels replace part of the imaging pixels 121 ina predetermined row among the pixel rows in the pixel array unit 111 tobe regularly arranged in a specific pattern.

[Example Configuration of Phase Difference Detection Pixel]

Next, an example configuration of the phase difference detection pixel311 in the pixel array unit 111 is described with reference to FIG. 20.

Note that description is omitted regarding parts of the phase differencedetection pixel 311 illustrated in FIG. 20 and the imaging pixel 121described with reference to FIG. 5 that are formed in a similar manner.

In the phase difference detection pixel 311, the light-shielding film210 is provided with an opening 321A for allowing the photodiode 201 toreceive light and an opening 321B for allowing the memory unit 202 toreceive light.

The opening 321A and the opening 321B preferably have the same shape. Inthe phase difference detection pixel 311, an on-chip lens 322 is formedin a position where the distance between its optical axis and a side ofthe opening 321A on the right side (the memory unit 202 side) becomesequal to the distance between its optical axis and a side of the opening321B on the left side (the photodiode 201 side).

That is, in the phase difference detection pixel 311, the openings 321Aand 321 B of the light-shielding film 210 are provided in positionssymmetrical to each other in the X direction in which the openings 321Aand 321B are arrayed, with respect to the optical axis of the on-chiplens 322.

Note that the position and size of the on-chip lens 322 in the phasedifference detection pixel 311 are preferably the same as the positionand size of the on-chip lens 213 in the imaging pixel 121.

Also with the above structure, it is possible to improve the precisionof phase difference detection while suppressing deterioration ofresolution in a solid-state imaging device 1 having the global shutterfunction and the phase difference AF function, because the area of thelight-receiving region of the phase difference detection pixel is notreduced and the number of effective pixels of the whole solid-stateimaging device need not be reduced.

The operation of the phase difference detection pixel 311 illustrated inFIG. 20 corresponds to the operation described with reference to FIG. 9and the operation described with reference to FIG. 10 performedsequentially. That is, in the phase difference detection pixel 311, inperforming phase difference detection, charge accumulated in thephotodiode 201 is read separately from charge accumulated in the memoryunit 202.

In the phase difference detection pixel 311 of FIG. 20, both thephotodiode 201 and the memory unit 202 are provided with an opening andneed not be shielded from light; therefore, as illustrated in FIG. 21,the phase difference detection pixel 311 can refrain from including thelight-shielding film 210.

In this case, in the phase difference detection pixel 311, thephotodiode 201 and the memory unit 202 are provided in positionssymmetrical to each other in the X direction in which the photodiode 201and the memory unit 202 are arrayed, with respect to the optical axis ofthe on-chip lens 322.

MODIFICATION EXAMPLE 7

By the way, in the configuration in which the memory unit 202 isprovided with an opening, among the above-described configurations ofthe phase difference detection pixels, the first transfer gate 203 isformed above the memory unit 202 to cover the upper portion of thememory unit 202; therefore, the memory unit 202 may not be able toobtain sufficient light-receiving properties.

Thus, for example, the phase difference detection pixel 122B is providedwith a first transfer gate 361 formed using a transparent conductivefilm, instead of the first transfer gate 203, as illustrated in FIG. 22.

Indium tin oxide (ITO), zinc oxide, tin oxide, or the like is used asthe material of the transparent conductive film. The transmittance ofthe first transfer gate 361 is preferably 80% or more, for example.

Such a configuration allows the memory unit 202 to obtain sufficientlight-receiving properties.

Note that this configuration can be applied to the phase differencedetection pixel 122B of FIG. 14 and the phase difference detection pixel311 of FIGS. 20 and 21 as well as the phase difference detection pixel122B of FIG. 7 (FIG. 8).

In the above-described configurations, the phase difference detectionpixels are shielded from light on the left side and the right side;however, depending on the pixel arrangement, the phase differencedetection pixels may be shielded from light on the upper side and thelower side, or may be obliquely shielded from light.

MODIFICATION EXAMPLE 8

[Example Configuration of Phase Difference Detection Pixel]

FIGS. 23 and 24 illustrate still another example configuration of thephase difference detection pixel 122. FIG. 23 is a top view, and FIG. 24is a cross-sectional view along the broken line a-b of FIG. 23.

Note that description is omitted regarding parts of the phase differencedetection pixels 122A and 122B illustrated in FIG. 23 and the phasedifference detection pixels 122A and 122B illustrated in FIG. 7 that areformed in a similar manner.

In the example configuration illustrated in FIG. 23, the phasedifference detection pixels 122A and 122B are integrally formed on onechip to be arranged adjacently in the X direction. In the phasedifference detection pixels 122A and 122B, the photodiodes 201 and thememory units 202 are formed in positions symmetrical to each other inthe X direction. In other words, the phase difference detection pixels122A and 122B are arranged such that, with respect to the Y axis servingas the boundary therebetween, constituent elements such as thephotodiodes 201 and the memory units 202 have mirror symmetry.

Specifically, while the photodiode 201 is formed on the left side andthe memory unit 202 is formed on the right side in the phase differencedetection pixel 122A, the memory unit 202 is formed on the left side andthe photodiode 201 is formed on the right side in the phase differencedetection pixel 122B.

The phase difference detection pixel 122A is provided with the opening221A for allowing the photodiode 201, which is formed on the left sideof the phase difference detection pixel 122A, to receive light. Thephase difference detection pixel 122B is provided with the opening 221Bfor allowing the photodiode 201, which is formed on the right side ofthe phase difference detection pixel 122B, to receive light.

The opening 221A and the opening 221B preferably have the same shape.

The on-chip lens 222 is formed in the same position in each of the phasedifference detection pixels 122A and 122B. Specifically, in the phasedifference detection pixels 122A and 122B, the on-chip lenses 222 areformed in positions where the distance between an optical axis of theon-chip lens 222 and a side of the opening 221A on the right side (thememory unit 202 side) in the phase difference detection pixel 122Abecomes equal to the distance between an optical axis of the on-chiplens 222 and a side of the opening 221B on the left side (the memoryunit 202 side) in the phase difference detection pixel 122B.

That is, in the pair of phase difference detection pixels 122A and 122B,the openings 221A and 221B of the light-shielding film 210 are providedin positions symmetrical to each other in the X direction in which thephase difference detection pixels 122A and 122B are arrayed, withrespect to the optical axes of the on-chip lenses 222.

Also with the above structure, it is possible to improve the precisionof phase difference detection while suppressing deterioration ofresolution in a solid-state imaging device 1 having the global shutterfunction and the phase difference AF function, because the area of thelight-receiving region of the phase difference detection pixel is notreduced and the number of effective pixels of the whole solid-stateimaging device need not be reduced.

Note that the operation of the phase difference detection pixels 122Aand 122B illustrated in FIG. 23 is similar to that described withreference to FIG. 10.

MODIFICATION EXAMPLE 9

[Example Configuration of Phase Difference Detection Pixel]

FIG. 25 illustrates another example configuration of the phasedifference detection pixel 122.

Note that description is omitted regarding parts of the phase differencedetection pixels 122A and 122B illustrated in FIG. 25 and the phasedifference detection pixels 122A and 122B illustrated in FIG. 7 that areformed in a similar manner.

In the example configuration illustrated in FIG. 25, the phasedifference detection pixels 122A and 122B are integrally formed on onechip to be arranged adjacently in the X direction. In the phasedifference detection pixels 122A and 122B, the photodiodes 201 and thememory units 202 are formed in positions symmetrical to each other inthe X direction. In other words, the phase difference detection pixels122A and 122B are arranged such that, with respect to the Y axis servingas the boundary therebetween, constituent elements such as thephotodiodes 201 and the memory units 202 have mirror symmetry.

Specifically, while the photodiode 201 is formed on the left side andthe memory unit 202 is formed on the right side in the phase differencedetection pixel 122A, the memory unit 202 is formed on the left side andthe photodiode 201 is formed on the right side in the phase differencedetection pixel 122B.

In the phase difference detection pixel 122A, approximately half of thephotodiode 201, which is formed on the left side of the phase differencedetection pixel 122A, on the upper side is provided with the opening221A. In the phase difference detection pixel 122B, approximately halfof the photodiode 201, which is formed on the right side of the phasedifference detection pixel 122B, on the upper side is provided with theopening 221B.

The opening 221A and the opening 221B preferably have the same shape.

The on-chip lens 222 is formed in the same position in each of the phasedifference detection pixels 122A and 122B. Specifically, in the phasedifference detection pixels 122A and 122B, the on-chip lenses 222 areformed in positions where the distance between an optical axis of theon-chip lens 222 and a side of the opening 221A on the right side (thememory unit 202 side) in the phase difference detection pixel 122Abecomes equal to the distance between an optical axis of the on-chiplens 222 and a side of the opening 221B on the left side (the photodiode201 side) in the phase difference detection pixel 122B.

That is, in the pair of phase difference detection pixels 122A and 122B,the openings 221A and 221B of the light-shielding film 210 are providedin positions symmetrical to each other in the X direction in which thephase difference detection pixels 122A and 122B are arrayed, withrespect to the optical axes of the on-chip lenses 222. In other words,the openings 221A and 221B also have mirror symmetry with respect to theY axis serving as the boundary between the phase difference detectionpixels 122A and 122B.

Also with the above structure, it is possible to improve the precisionof phase difference detection while suppressing deterioration ofresolution in a solid-state imaging device 1 having the global shutterfunction and the phase difference AF function, because the area of thelight-receiving region of the phase difference detection pixel is notreduced and the number of effective pixels of the whole solid-stateimaging device need not be reduced.

Note that the operation of each of the phase difference detection pixels122A and 122B illustrated in FIG. 25 is similar to that described withreference to FIG. 10.

MODIFICATION EXAMPLE 10

[Example Configuration of Phase Difference Detection Pixel]

FIG. 26 illustrates still another example configuration of the phasedifference detection pixel 122.

Description is omitted regarding parts of the phase difference detectionpixels 122A and 122B illustrated in FIG. 26 and the phase differencedetection pixels 122A and 122B illustrated in FIG. 7 that are formed ina similar manner.

In the example configuration illustrated in FIG. 26, like the phasedifference detection pixels 122A and 122B illustrated in FIG. 23(Modification example 8), the phase difference detection pixels 122A and122B are integrally formed on one chip to be arranged adjacently, andare arranged such that, with respect to the Y axis serving as theboundary therebetween, constituent elements have mirror symmetry.

Note that the floating diffusion region 204, the reset transistor 206,the amplifier transistor 207, and the selection transistor 208 areshared by two pixels, the phase difference detection pixels 122A and122B.

Also with the above structure, it is possible to improve the precisionof phase difference detection while suppressing deterioration ofresolution in a solid-state imaging device 1 having the global shutterfunction and the phase difference AF function, because the area of thelight-receiving region of the phase difference detection pixel is notreduced and the number of effective pixels of the whole solid-stateimaging device need not be reduced.

Note that the operation of the phase difference detection pixels 122Aand 122B illustrated in FIG. 26 is similar to that described withreference to FIG. 10.

MODIFICATION EXAMPLE 11

[Example Configuration of Phase Difference Detection Pixel]

FIG. 27 illustrates still another example configuration of the phasedifference detection pixel 122.

In the example configuration of FIG. 27, a configuration for mirrorsymmetry with respect to the X axis is added to the lower side of theexample configuration illustrated in FIG. 26 (Modification example 10);thus, four pixels, the phase difference detection pixels 122A1, 122A2,122B1, and 122B2, are integrally formed on one chip to be arrangedadjacently in two pixels×two pixels. For the example configuration ofFIG. 27, the imaging pixels 121 of at least two consecutive rows orcolumns in the pixel array unit 111 need to be replaced with the phasedifference detection pixels 122.

In the example configuration of FIG. 27, the floating diffusion region204, the reset transistor 206, the amplifier transistor 207, and theselection transistor 208 are shared by four pixels, the phase differencedetection pixels 122A1, 122A2, 122B1, and 122B2.

Also with the above structure, it is possible to improve the precisionof phase difference detection while suppressing deterioration ofresolution in a solid-state imaging device 1 having the global shutterfunction and the phase difference AF function, because the area of thelight-receiving region of the phase difference detection pixel is notreduced and the number of effective pixels of the whole solid-stateimaging device need not be reduced.

Note that the operation of the phase difference detection pixels 122A1,122A2, 122B1, and 122B2 illustrated in FIG. 27 is similar to thatdescribed with reference to FIG. 10.

MODIFICATION EXAMPLE 12

[Example Configuration of Phase Difference Detection Pixel]

FIG. 28 illustrates still another example configuration of the phasedifference detection pixel 122.

The example configuration of FIG. 28 is obtained by rotating the exampleconfiguration illustrated in FIG. 23 (Modification example 8) by 90degrees using the Z axis as a rotation axis. That is, the phasedifference detection pixels 122A and 122B illustrated in FIG. 28 areintegrally formed on one chip to be arranged adjacently in the Ydirection. In the phase difference detection pixels 122A and 122B, thephotodiodes 201 and the memory units 202 are formed in positionssymmetrical to each other in the Y direction. In other words, the phasedifference detection pixels 122A and 122B are arranged such that, withrespect to the X axis serving as the boundary therebetween, constituentelements such as the photodiodes 201 and the memory units 202 havemirror symmetry.

For the example configuration of FIG. 28, the phase difference detectionpixels 122 are arranged side by side in the Y direction (columndirection) in the pixel array unit 111.

Also with the above structure, it is possible to improve the precisionof phase difference detection while suppressing deterioration ofresolution in a solid-state imaging device 1 having the global shutterfunction and the phase difference AF function, because the area of thelight-receiving region of the phase difference detection pixel is notreduced and the number of effective pixels of the whole solid-stateimaging device need not be reduced.

Note that the operation of the phase difference detection pixels 122Aand 122B illustrated in FIG. 28 is similar to that described withreference to FIG. 10.

MODIFICATION EXAMPLE 13

[Example Configuration of Phase Difference Detection Pixel]

FIG. 29 illustrates still another example configuration of the phasedifference detection pixel 122.

In the example configuration of FIG. 29, two configurations obtained byrotating the example configuration illustrated in FIG. 25 (Modificationexample 9) by 90 degrees using the Z axis as a rotation axis arearranged side by side in the X-axis direction; thus, four pixels, thephase difference detection pixels 122A1, 122A2, 122B1, and 122B2, areintegrally formed on one chip to be arranged adjacently in twopixels×two pixels.

For the example configuration of FIG. 29, the imaging pixels 121 of atleast two consecutive rows or columns in the pixel array unit 111 needto be replaced with the phase difference detection pixels 122.

Also with the above structure, it is possible to improve the precisionof phase difference detection while suppressing deterioration ofresolution in a solid-state imaging device 1 having the global shutterfunction and the phase difference AF function, because the area of thelight-receiving region of the phase difference detection pixel is notreduced and the number of effective pixels of the whole solid-stateimaging device need not be reduced.

Note that the operation of the phase difference detection pixels 122A1,122A2, 122B1, and 122B2 illustrated in FIG. 29 is similar to thatdescribed with reference to FIG. 10.

MODIFICATION EXAMPLE 14

[Example Configuration of Phase Difference Detection Pixel]

FIG. 30 illustrates still another example configuration of the phasedifference detection pixel 122.

In the example configuration of FIG. 30, a configuration for mirrorsymmetry with respect to the X axis is added to the right side of theexample configuration illustrated in FIG. 28 (Modification example 12);thus, four pixels, the phase difference detection pixels 122A1, 122A2,122B1, and 122B2, are integrally formed on one chip to be arrangedadjacently in two pixels×two pixels. For the example configuration ofFIG. 30, the imaging pixels 121 of at least two consecutive rows orcolumns in the pixel array unit 111 need to be replaced with the phasedifference detection pixels 122.

In the example configuration of FIG. 30, the floating diffusion region204, the reset transistor 206, the amplifier transistor 207, and theselection transistor 208 are shared by four pixels, the phase differencedetection pixels 122A1, 122A2, 122B1, and 122B2.

Also with the above structure, it is possible to improve the precisionof phase difference detection while suppressing deterioration ofresolution in a solid-state imaging device 1 having the global shutterfunction and the phase difference AF function, because the area of thelight-receiving region of the phase difference detection pixel is notreduced and the number of effective pixels of the whole solid-stateimaging device need not be reduced.

Note that the operation of the phase difference detection pixels 122A1,122A2, 122B1, and 122B2 illustrated in FIG. 30 is similar to thatdescribed with reference to FIG. 10.

MODIFICATION EXAMPLE 15

[Example Configuration of Phase Difference Detection Pixel]

FIG. 31 illustrates still another example configuration of the phasedifference detection pixel 122.

In the example configuration of FIG. 31, a configuration for mirrorsymmetry with respect to the X axis is added to the right side of aconfiguration obtained by rotating the example configuration illustratedin FIG. 25 (Modification example 9) by 90 degrees using the Z axis as arotation axis; thus, four pixels, the phase difference detection pixels122A1, 122A2, 122B1, and 122B2, are integrally formed on one chip to bearranged adjacently in two pixels×two pixels. For the exampleconfiguration of FIG. 31, the imaging pixels 121 of at least twoconsecutive rows or columns in the pixel array unit 111 need to bereplaced with the phase difference detection pixels 122.

In the example configuration of FIG. 31, the floating diffusion region204, the reset transistor 206, the amplifier transistor 207, and theselection transistor 208 are shared by four pixels, the phase differencedetection pixels 122A1, 122A2, 122B1, and 122B2.

Also with the above structure, it is possible to improve the precisionof phase difference detection while suppressing deterioration ofresolution in a solid-state imaging device 1 having the global shutterfunction and the phase difference AF function, because the area of thelight-receiving region of the phase difference detection pixel is notreduced and the number of effective pixels of the whole solid-stateimaging device need not be reduced.

Note that the operation of the phase difference detection pixels 122A1,122A2, 122B1, and 122B2 illustrated in FIG. 31 is similar to thatdescribed with reference to FIG. 10.

Note that this embodiment shows examples in which the floating diffusionregion 204, the reset transistor 206, the amplifier transistor 207, andthe selection transistor 208 are shared by a plurality of pixels foronly the phase difference detection pixels 122; however, these can alsobe shared by a plurality of imaging pixels 121.

The present technology is not limited to the above embodiment, and mayassume various modifications within the scope of the present technology.Additionally, the present technology may also be configured as below.

(1)

A solid-state imaging device including:

a pixel array unit including, as pixels including an on-chip lens, aphotoelectric conversion unit, and a charge accumulation unit, imagingpixels for generating a captured image and phase difference detectionpixels for performing phase difference detection arrayed therein; and

a driving control unit configured to control driving of the pixels,wherein the imaging pixel is formed with the charge accumulation unitshielded from light, and

wherein the phase difference detection pixel is formed in a manner thatat least part of at least one of the photoelectric conversion unit andthe charge accumulation unit refrains from being shielded from light.

(2)

The solid-state imaging device according to (1), wherein the drivingcontrol unit

reads, in performing the phase difference detection, charge accumulatedin at least part of at least one of the photoelectric conversion unitand the charge accumulation unit in the phase difference detectionpixels, and

performs, in generating the captured image, accumulation of charge in atleast the imaging pixels simultaneously.

(3)

The solid-state imaging device according to (1) or (2),

wherein the phase difference detection pixel includes a light-shieldingfilm that is provided with an opening in at least part of at least oneof the photoelectric conversion unit and the charge accumulation unit,and

wherein, in a pair of the phase difference detection pixels, theopenings are provided in positions symmetrical to each other in a firstdirection in which the pair of phase difference detection pixels arearrayed, with respect to optical axes of the on-chip lenses.

(4)

The solid-state imaging device according to any of (1) to (3), whereinthe charge accumulation unit is formed as a charge retention unitconfigured to retain charge from the photoelectric conversion unit.

(5)

The solid-state imaging device according to (4),

wherein the photoelectric conversion unit and the charge retention unitare formed side by side in the first direction, and

wherein the photoelectric conversion unit is provided with the openingin one of the pair of phase difference detection pixels, and the chargeretention unit is provided with the opening in the other of the pair ofphase difference detection pixels.

(6)

The solid-state imaging device according to (5), wherein, in performingthe phase difference detection, the driving control unit reads chargeaccumulated in the photoelectric conversion unit in the one phasedifference detection pixel, and reads charge accumulated in the chargeretention unit in the other phase difference detection pixel.

(7)

The solid-state imaging device according to (6), wherein the drivingcontrol unit controls driving of the one phase difference detectionpixel and the other phase difference detection pixel in a manner that aproduct of sensitivity of the photoelectric conversion unit andaccumulation time in the one phase difference detection pixel becomesequal to a product of sensitivity of the charge retention unit andaccumulation time in the other phase difference detection pixel.

(8)

The solid-state imaging device according to (4),

wherein the photoelectric conversion unit and the charge retention unitare formed side by side in the first direction, and

wherein approximately half of the photoelectric conversion unit in thefirst direction is provided with the opening in one of the pair of phasedifference detection pixels, and the other approximately half of thephotoelectric conversion unit in the first direction is provided withthe opening in the other of the pair of phase difference detectionpixels.

(9)

The solid-state imaging device according to (4),

wherein, in the pair of phase difference detection pixels, thephotoelectric conversion units and the charge retention units are formedin positions with mirror symmetry with respect to a boundary between thepair of phase difference detection pixels, and

wherein, in each of the pair of phase difference detection pixels, thephotoelectric conversion unit is provided with the opening.

(10)

The solid-state imaging device according to (4),

wherein the photoelectric conversion unit and the charge retention unitare formed side by side in a second direction perpendicular to the firstdirection, and

wherein approximately half of the photoelectric conversion unit and thecharge retention unit in the first direction is provided with theopening in one of the pair of phase difference detection pixels, and theother approximately half of the photoelectric conversion unit and thecharge retention unit in the first direction is provided with theopening in the other of the pair of phase difference detection pixels.

(11)

The solid-state imaging device according to (10), wherein, in performingthe phase difference detection, the driving control unit reads chargeaccumulated in the photoelectric conversion unit and the chargeretention unit in the one phase difference detection pixel together, andreads charge accumulated in the photoelectric conversion unit and thecharge retention unit in the other phase difference detection pixeltogether.

(12)

The solid-state imaging device according to (3),

wherein, in the phase difference detection pixel, the chargeaccumulation unit is formed as another photoelectric conversion unitside by side with the photoelectric conversion unit in the firstdirection, and

wherein the photoelectric conversion unit is provided with the openingin one of the pair of phase difference detection pixels, and the otherphotoelectric conversion unit is provided with the opening in the otherof the pair of phase difference detection pixels.

(13)

The solid-state imaging device according to (1) or (2),

wherein, in the phase difference detection pixel, the photoelectricconversion unit and the charge accumulation unit are formed in positionssymmetrical to each other in a predetermined direction, with respect toan optical axis of the on-chip lens, and

wherein, in performing the phase difference detection, the drivingcontrol unit reads charge accumulated in the photoelectric conversionunit in the phase difference detection pixel and charge accumulated inthe charge retention unit in the phase difference detection pixelseparately.

(14)

The solid-state imaging device according to (13), wherein the chargeaccumulation unit is formed as a charge retention unit configured toretain charge from the photoelectric conversion unit.

(15)

The solid-state imaging device according to (13) or (14),

wherein the phase difference detection pixel includes a light-shieldingfilm that is provided with openings in part of the photoelectricconversion unit and the charge accumulation unit, and

wherein the openings are provided in positions symmetrical to each otherin the predetermined direction, with respect to an optical axis of theon-chip lens.

(16)

The solid-state imaging device according to (1) or (2),

wherein the charge accumulation unit is formed as a charge retentionunit configured to retain charge from the photoelectric conversion unit,

wherein the phase difference detection pixel includes a transferelectrode configured to transfer charge from the photoelectricconversion unit to the charge retention unit above the charge retentionunit, and

wherein the transfer electrode is formed using a transparent conductivefilm.

(17)

The solid-state imaging device according to any of (1) to (16), whereinat least one of the imaging pixel and the phase difference detectionpixel shares constituent elements among a plurality of pixels.

(18)

The solid-state imaging device according to (17), wherein theconstituent elements shared by the plurality of pixels include at leastone of a floating diffusion region, a reset transistor, an amplifiertransistor, and a selection transistor.

(19)

A driving method of a solid-state imaging device, the solid-stateimaging device including

a pixel array unit including, as pixels including an on-chip lens, aphotoelectric conversion unit, and a charge accumulation unit, imagingpixels for generating a captured image and phase difference detectionpixels for performing phase difference detection arrayed therein, and

-   -   a driving control unit configured to control driving of the        pixels,    -   wherein the imaging pixel is formed with the charge accumulation        unit shielded from light, and    -   wherein the phase difference detection pixel is formed in a        manner that at least part of at least one of the photoelectric        conversion unit and the charge accumulation unit refrains from        being shielded from light,

the driving method including the steps of:

reading, in the phase difference detection performed by the solid-stateimaging device, charge accumulated in at least part of at least one ofthe photoelectric conversion unit and the charge accumulation unit inthe phase difference detection pixels; and

performing, in generation of the captured image by the solid-stateimaging device, accumulation of charge in at least the imaging pixelssimultaneously.

(20)

An electronic apparatus including

a solid-state imaging device including

-   -   a pixel array unit including, as pixels including an on-chip        lens, a photoelectric conversion unit, and a charge accumulation        unit, imaging pixels for generating a captured image and phase        difference detection pixels for performing phase difference        detection arrayed therein, and    -   a driving control unit configured to control driving of the        pixels,    -   wherein the imaging pixel is formed with the charge accumulation        unit shielded from light, and    -   wherein the phase difference detection pixel is formed in a        manner that at least part of at least one of the photoelectric        conversion unit and the charge accumulation unit refrains from        being shielded from light.

REFERENCE SIGNS LIST

-   1 electronic apparatus-   14 image sensor-   111 pixel array unit-   121 imaging pixel-   122 phase difference detection pixel-   201 photodiode-   202 memory unit-   203 first transfer gate-   210 light-shielding film-   211 opening-   213 on-chip lens-   221A, 221B opening-   222 on-chip lens-   231 photodiode-   311 phase difference detection pixel-   321A, 321B opening-   322 on-chip lens-   361 first transfer gate

The invention claimed is:
 1. A light detecting device, comprising: a first pixel including: a first photoelectric conversion region; and a first charge accumulation region; a second pixel including: a second photoelectric conversion region; and a second charge accumulation region; a first light shielding portion disposed above a light receiving surface of the first charge accumulation region and the second charge accumulation region; a second light shielding portion; and a third light shielding portion, wherein an end of the second light shielding portion and an end of the third light shielding portion are connected to the first light shielding portion in a cross-sectional view.
 2. The light detecting device of claim 1, wherein the first pixel includes a first floating diffusion region and the second pixel includes a second floating diffusion region.
 3. The light detecting device of claim 1, wherein the first charge accumulation region and the second accumulation region are adjacent to each other.
 4. The light detecting device of claim 3, wherein the second light shielding portion, the first charge accumulation region, the second accumulation region, and the third light shielding portion are arranged in this order in a first direction.
 5. The light detecting device of claim 4, wherein the first photoelectric conversion region, the first charge accumulation region, the second accumulation region, and the second photoelectric conversion region are arranged in this order in the first direction.
 6. The light detecting device of claim 1, further comprising: a wiring layer is disposed above the first light shielding portion.
 7. The light detecting device of claim 6, wherein a wiring of the wiring layer is disposed directly above the first light shielding portion.
 8. The light detecting device of claim 1, wherein the first pixel includes a first reset transistor, a first amplifier transistor, and a first select transistor, wherein the first select transistor, the first amplifier transistor, and the first reset transistor are arranged in a first direction in which the first photoelectric conversion region and the first charge accumulation region are arranged.
 9. The light detecting device of claim 8, wherein the second pixel includes a second reset transistor, a second amplifier transistor, and a second select transistor, wherein the second reset transistor, the second amplifier transistor, and the second reset transistor are arranged in the first direction.
 10. The light detecting device of claim 1, wherein the first light shielding portion is disposed above one half of a light receiving surface of the first photoelectric conversion region.
 11. The light detecting device of claim 10, wherein the first light shielding portion is disposed near the first charge accumulation region.
 12. The light detecting device of claim 10, wherein the first light shielding portion is disposed near a pixel transistor region of the first pixel including a first reset transistor, a first amplifier transistor, and a first select transistor.
 13. The light detecting device of claim 1, further comprising: a third pixel disposed adjacent to the first pixel and including third photoelectric conversion region and a third charge accumulation region, wherein a pixel transistor region of the first pixel is disposed between the first photoelectric conversion region and the third photoelectric conversion region.
 14. The light detecting device of claim 1, wherein the first light shielding portion extends in a first direction, and the second and third light shielding portions extend in a second direction perpendicular to the first direction.
 15. The light detecting device of claim 14, wherein the second and third light shielding portions are connected to opposite ends of the first light shielding portion.
 16. The light detecting device of claim 1, wherein the first light shielding portion is disposed above a first gate of a first transistor that transfers charge from the first photoelectric conversion region to the first charge accumulation region.
 17. The light detecting device of claim 1, wherein the first light shielding portion is disposed above a second gate of a second transistor that transfers charge from the second photoelectric conversion region to the second charge accumulation region.
 18. An apparatus, comprising: a lens unit; and a light detecting device including: a first pixel including: a first photoelectric conversion region; and a first charge accumulation region; a second pixel including: a second photoelectric conversion region; and a second charge accumulation region; a first light shielding portion disposed above a light receiving surface of the first charge accumulation region and the second charge accumulation region; a second light shielding portion; and a third light shielding portion, wherein an end of the second light shielding portion and an end of the third light shielding portion are connected to the first light shielding portion in a cross-sectional view.
 19. A light detecting device, comprising: a first pixel including: a first photoelectric conversion region; and a first charge accumulation region; a second pixel including: a second photoelectric conversion region; and a second charge accumulation region; and a U-shaped shield disposed above the first charge accumulation region and the second charge accumulation region.
 20. The light detecting device of claim 19, wherein the U-shaped shield includes a flat base portion and first and second leg portions extending from the base portion. 